HgCl2 Toxicity on Cultured Renal Tubular Cells of Rabbit

Lee, Jung Young; Lee, Seong Beom; Lee, Suk Hyung; Park, Won Sang; Yoo, Nam Jin; Kim, Sang Ho; Kim, Choo Soung

Abstract

To understand the mechanism of cell injury when exposed to HgCl2, monitoring of cytosolic ionized free Ca2+([Ca2+]i), viability test, measurement of the amount of ATP, and Ca-ATPase activity were evaluated in cultured rabbit renal tubular cells(RTC) exposed to HgCl2. The results were as follows: 1) HgCl2 was cytotoxic to rabbit RTC at all doses except 10 uM and the rate of killing displayed a dose- and time-dependent relationship. 2) The absence of extracellular Ca provided partial protection from irreversible injury induced by HgCl2. 3) The increasing pattem of [Ca2+]i varied according to the concentrations of HgCl2. At the low concentrations of HgCl2 (2.5-10 microM), the level of [Ca2+]i increased slowly over the flat 2-3 min and then achieved plateau-state. In contrast, at the high concentrations of HgCl2 (25-100 microM) the level of [Ca2+]i achieved peak within 1 min and then decreased to a plateau state under normal concentrations. 4) The level of ATP was decreased to 27.5% of that of normal control cells within 3 min by using a treatment of 100 microM HgCl2. 5) HgCl2 did not affect the Ca2+ ATPase activity by enzyme histochemical observation. These findings suggest that the elevation of [Ca2+]i in response to the HgCl2-induced injury is an important event in accelerating injury that ultimately leads to cell death. But other possibilities such as HgCl2 might have direct deleterious effects on the also should be considered.